Split the difference and go 3/16".
hahaha
It's like you read my mind Shardian!
I been reading some back posts here and it seems like 3/16" and 1/4" come up the most.
ps. On a side not I see pinball machine glass is 3/16". That is a very big piece of glass, you know people are going to be leaning on that at some point and time.